In a sensor device having a sensor chip, in which a movable portion displaced by a dynamic amount such as acceleration, angular velocity or pressure, etc. is formed on one surface side of a semiconductor substrate.
For example, an angular velocity sensor having a vibrator constructed with a beam structural body having a comb teeth shape, an acceleration sensor (e.g., JP-A-2004-286615) having a movable electrode and a fixing electrode constructed with a beam structural body having a comb teeth shape, a pressure sensor having a semiconductor diaphragm, etc. are proposed as such a sensor device.
Here, in such a sensor device, the circuit chip constructed with an IC chip separated from the sensor chip, etc. is arranged for the purpose of processing of a signal outputted from the sensor chip, etc. In this case, a stack structure for laminating the sensor chip and the circuit chip and for electrically connecting both these chips is adopted to make the body of the sensor device compact.
In a sensor device shown in FIG. 15, a circuit chip 200 is fixed to an interior of a package 300 sealed by a cover portion 320, through an adhesive 1. A sensor chip 100 is fixed onto this circuit chip 200 through an adhesive sheet 2, etc.
A movable portion 20 as a sensor element, (i.e., a sensing portion) is formed on an upper surface of the sensor chip 100. Then, the sensor chip 100 and the circuit chip 200, and the circuit chip 200 and the package 300 are electrically connected using wires 3 through wire bonding.
However, as shown in FIG. 15, in this sensor device, the sensor chip 100 and the circuit chip 200 are electrically connected through the wire 3. Therefore, the wire 3 as this electrical connecting portion is easily deformed by an impact applied from the exterior to the sensor device.
When the wire 3 is deformed in this way, a sensor output outputted from the sensor device is influenced by the change of parasitic capacity due to the deformation of this wire 3, and is easily changed.
Further, when foreign matters existing within the package 300 are moved and are attached to the movable portion 20 by the application of the impact, there are problems in that movable characteristics of the movable portion 20 are obstructed and no preferable sensor characteristics are obtained.